Make Your Own Cellphone for $120 in Parts, Plus SIM Card: It's Not Rocket Science

But buying the parts and assembling the phone might not yet be a task for casual tinkerers working alone at home. "Things did not always go as expected," Grossman said. "The first time I went through it I had the button for the No. 8 key on the dial pad rotated 90 degrees. So we plugged it in and turned it on and were pushing the buttons and none of the other buttons would work, because the No. 8 button was pressed all the time it was rotated, and you can only press one button at a time."

And that wasn't all. When Grossman began to laser-cut the wood for the case, it caught fire. "We used the wrong wood, and it burned too easily," she said.

The result of an afternoon's work was a phone that looked downright artisanal, "like a brick of wood with some buttons on it," Grossman said, "but I love it."

The phone makes and receives calls, sends and receives texts, and includes a phone book that stores a few hundred numbers, a clock, call logs and a rechargeable battery, all for a cost of about $120 in parts and the price of a SIM card, which can range from $1 to $30. With its retro antenna and 84-by-48 monochrome pixel display screen, it's reminiscent of the Nokia phones, circa 2003.

Now in its second prototype (the first version could only make and receive calls), the DIY Cellphone is likely to remain lab-bound for at least the next year.

"I want to get it out to more people," Mellis said. He envisions the possibly of a kit, "where you solder it yourself, or something where the basic stuff is already soldered together for you and you can add features. That might be a little more creative. You can add on whatever you want instead of just soldering this thing."

He's hoping to work with Arduino, the open source hardware and software developer that he helped launch in 2005, or possibly SparkFun Electronics, to develop a kit that could be commercially released. "Both companies make similar sorts of products for various audiences," Mellis said.

But the DIY Cellphone might have a rough ride in a market caught up in more power, more features and bigger screens.

"It sounds much more like an educational opportunity than a commercial one," said Charles Golvin, a principal wireless analyst at Forrester Research. "The mass audience of people when it comes to their phones want something that's delivering all the latest capabilities and access to a wide range of applications.

"It's in the same spirit of turning cellular connectivity, together with the processing and graphics and other things, into a tool that somebody could use to hack together some wacky design."

Mellis said he had to walk a balance between creating a phone that could do everything and keeping it simple enough so people could build it themselves. He said he uses his DIY Cellphone every day as his main phone and has repurposed his old iPhone to listen to podcasts at home. "I'm kind of enjoying not having to deal with email all the time," he said.

Grossman said she's now thinking of changing the wooden case on her homegrown phone to clear resin, "so that you can see the guts."

Much as she loves her DIY phone, she has no plans to give up her Android smartphone.